Backup system and backup method

Abstract

A backup system includes a plurality of backup storage devices for storing backup data of backup target data stored in a storage device. The plurality of backup storage devices are classified as backup storage devices belonging to either a primary layer or a secondary layer. In the backup system, the backup target data is backed up by the storage device storing primary backup data, which is backup data of the backup target data, in the backup storage device belonging to the primary layer, and the backup storage device belonging to the primary layer storing secondary backup data, which is backup data of the primary backup data, in the backup storage device belonging to the secondary layer.

What is claimed is: 
     
         1 . A backup system comprising a plurality of backup storage devices for storing backup data of backup target data stored in a storage device, wherein
 the plurality of backup storage devices are classified as backup storage devices belonging to either a primary layer or a secondary layer, and   the backup target data is backed up by the storage device storing primary backup data, which is backup data of the backup target data, in the backup storage device belonging to the primary layer, and the backup storage device belonging to the primary layer storing secondary backup data, which is backup data of the primary backup data, in the backup storage device belonging to the secondary layer.   
     
     
         2 . The backup system according to  claim 1 , wherein the storage device determines whether or not a connection state between the storage device and a primary layer backup storage device, which is the backup storage device which belongs to the primary layer and stores the primary backup data, is normal, and determines whether or not a connection state between the primary layer backup storage device and a secondary layer backup storage device, which is the backup storage device which belongs to the secondary layer and stores the secondary backup data, is normal. 
     
     
         3 . The backup system according to  claim 2 , wherein
 the storage device switches a storage destination of the primary backup data to another backup storage device belonging to the primary layer in a case where the connection state between the storage device and the primary layer backup storage device is not normal,   the secondary layer backup storage device transmits a copy of the secondary backup data to the other backup storage device belonging to the primary layer as a switching destination,   the other backup storage device belonging to the primary layer as the switching destination restores the primary backup data from the copy of the secondary backup data,   the primary layer backup storage device
 switches a storage destination of the secondary backup data to another backup storage device belonging to the secondary layer in a case where the connection state between the primary layer backup storage device and the secondary layer backup storage device is not normal, and 
 transmits a copy of the primary backup data to the other backup storage device belonging to the secondary layer as a switching destination, and 
   the other backup storage device belonging to the secondary layer as the switching destination restores the secondary backup data from the copy of the primary backup data.   
     
     
         4 . The backup system according to  claim 3 , wherein
 the storage device
 in a case where the connection state between the storage device and the primary layer backup storage device is not normal, determines whether or not there is another backup storage device belonging to the primary layer and capable of being switched to, 
 in a case where there is the other backup storage device belonging to the primary layer and capable of being switched to, switches the storage destination of the primary backup data to the other backup storage device belonging to the primary layer, and 
 in a case where there is no another backup storage device belonging to the primary layer and capable of being switched to, generates an alert regarding an abnormal state of a backup relationship. 
   
     
     
         5 . The backup system according to  claim 3 , wherein
 the primary layer backup storage device
 in a case where the connection state between the primary layer backup storage device and the secondary layer backup storage device is not normal, determines whether or not there is another backup storage device belonging to the secondary layer and capable of being switched to, 
 in a case where there is the other backup storage device belonging to the secondary layer and capable of being switched to, switches the storage destination of the secondary backup data to the other backup storage device belonging to the secondary layer, and 
 in a case where there is no another backup storage device belonging to the secondary layer and capable of being switched to, generates an alert regarding an abnormal state of a backup relationship. 
   
     
     
         6 . The backup system according to  claim 3 , wherein
 the storage device
 in a case where the connection state between the storage device and the primary layer backup storage device is not normal, determines whether or not there is another backup storage device belonging to the primary layer and capable of being switched to, 
 in a case where there are a plurality of other backup storage devices belonging to the primary layer and capable of being switched to, calculates operation scores for evaluating operation states of the plurality of other backup storage devices, and selects another backup storage device as a switching destination from among the plurality of other backup storage devices on a basis of the operation scores, and 
 switches the storage destination of the primary backup data to the selected another backup storage device belonging to the primary layer. 
   
     
     
         7 . The backup system according to  claim 3 , wherein
 the primary layer backup storage device
 in a case where the connection state between the primary layer backup storage device and the secondary layer backup storage device is not normal, determines whether or not there is another backup storage device belonging to the secondary layer and capable of being switched to, 
 in a case where there are a plurality of other backup storage devices belonging to the secondary layer and capable of being switched to, calculate operation scores for evaluating operation states of the plurality of other backup storage devices, and selects another backup storage device as a switching destination from among the plurality of other backup storage devices on a basis of the operation scores, and 
 switches the storage destination of the secondary backup data to the selected another backup storage device belonging to the secondary layer. 
   
     
     
         8 . The backup system according to  claim 3 , wherein
 the storage device
 after the storage destination of the primary backup data is switched to the other backup storage device belonging to the primary layer, determines whether or not a connection state between the storage device and the backup storage device belonging to the primary layer before switching is normal, and 
 in a case where the connection state between the storage device and the backup storage device belonging to the primary layer before switching is normal, switches the storage destination of the primary backup data from the other backup storage device belonging to the primary layer to the backup storage device belonging to the primary layer before switching. 
   
     
     
         9 . The backup system according to  claim 3 , wherein
 after the storage destination of the secondary backup data is switched to the other backup storage device belonging to the secondary layer, the storage device determines whether or not a connection state between the primary layer backup storage device and the backup storage device belonging to the secondary layer before switching is normal, and   in a case where the connection state between the primary layer backup storage device and the backup storage device belonging to the secondary layer before switching is normal, the primary layer backup storage device switches the storage destination of the secondary backup data from the other backup storage device belonging to the secondary layer to the backup storage device belonging to the secondary layer before switching.   
     
     
         10 . The backup system according to  claim 8 , wherein
 the storage device
 in a case where the connection state between the storage device and the backup storage device belonging to the primary layer before switching is normal, calculates operation scores for calculating operation states of the backup storage device belonging to the primary layer before switching and another backup storage device belonging to the primary layer after switching, and 
 in a case where the operation score of the backup storage device belonging to the primary layer before switching is superior to the operation score of the other backup storage device belonging to the primary layer, switches the storage destination of the primary backup data from the other backup storage device belonging to the primary layer to the backup storage device belonging to the primary layer before switching. 
   
     
     
         11 . The backup system according to  claim 9 , wherein
 the primary layer backup storage device
 in a case where the connection state between the primary layer backup storage device and the backup storage device belonging to the secondary layer before switching is normal, calculates operation scores for calculating operation states of the backup storage device belonging to the secondary layer before switching and another backup storage device belonging to the secondary layer after switching, and 
 in a case where the operation score of the backup storage device belonging to the secondary layer before switching is superior to the operation score of the other backup storage device belonging to the secondary layer, switches the storage destination of the secondary backup data from the other backup storage device belonging to the secondary layer to the backup storage device belonging to the secondary layer before switching. 
   
     
     
         12 . The backup system according to  claim 1 , wherein
 the storage device
 calculates an operation score for calculating an operation state of another backup storage device belonging to the primary layer, and 
 determines whether or not to switch a storage destination of the primary backup data to another backup storage device belonging to the primary layer on a basis of the operation score, and switches the storage destination of the primary backup data to the other backup storage device belonging to the primary layer according to a determination result, 
 the backup storage device which belongs to the secondary layer and stores the secondary backup data transmits a copy of the secondary backup data to the other backup storage device belonging to the primary layer as a switching destination, 
 the other backup storage device belonging to the primary layer as the switching destination restores the primary backup data from the copy of the secondary backup data, 
 the backup storage device which belongs to the primary layer and stores the primary backup data
 calculates an operation score for calculating an operation state of another backup storage device belonging to the secondary layer, and 
 determines whether or not to switch a storage destination of the secondary backup data to the other backup storage device belonging to the secondary layer on a basis of the operation score, and switches the storage destination of the secondary backup data to the other backup storage device belonging to the secondary layer according to a determination result, 
 
 the backup storage device which belongs to the primary layer and stores the primary backup data transmits a copy of the primary backup data to the other backup storage device belonging to the secondary layer as a switching destination, and 
 the other backup storage device belonging to the secondary layer as the switching destination restores the secondary backup data from the copy of the primary backup data. 
   
     
     
         13 . A backup method using a plurality of backup storage devices for storing backup data of backup target data stored in a storage device, wherein
 the plurality of backup storage devices are classified as backup storage devices belonging to either a primary layer or a secondary layer, and   the backup target data is backed up by the storage device storing primary backup data, which is backup data of the backup target data, in the backup storage device belonging to the primary layer, and the backup storage device belonging to the primary layer storing secondary backup data, which is backup data of the primary backup data, in the backup storage device belonging to the secondary layer.